Silicic acid: The omniscient molecule.

We contend that silicic acid is a much under-valued molecule and specifically in the context of its role in establishing and maintaining life on Earth. Silicic acid can also be an ill-understood molecule with its chemistry all too often confused with that of either silicates or silica. Herein we (i) provide a working definition for silicic acid; (ii) identify its omnipresent role in biochemical evolution in excluding aluminium from biota and providing adventitious benefits through biological silicification and (iii) explain how the silicic acid cycle is intrinsic to climate change.